diff --git a/gajim.spec b/gajim.spec
index 594114c..67901f1 100644
--- a/gajim.spec
+++ b/gajim.spec
@@ -66,6 +66,13 @@ Gajim does not require GNOME to run, even though it exists with it nicely.
 %pyproject_install
 %pyproject_save_files gajim
 
+# RHEL <= 9 doesn't support .desktop files with version 1.5,
+# see: https://bugzilla.redhat.com/show_bug.cgi?id=2107278
+%if 0%{?rhel} && 0%{?rhel} <= 9
+sed -e 's/^SingleMainWindow=/X-GNOME-SingleWindow=/' \
+    -i %{buildroot}/%{_datadir}/applications/%{appid}.desktop
+%endif
+
 desktop-file-validate %{buildroot}/%{_datadir}/applications/%{appid}.desktop
 appstream-util validate-relax --nonet %{buildroot}%{_datadir}/metainfo/%{appid}.appdata.xml